foo.cc: In function 'int main()':
foo.cc:18:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   18 |   scanf("%d",&l);
      |   ~~~~~^~~~~~~~~
foo.cc:19:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   19 |   scanf("%d%d%d",&s,&t,&m);
      |   ~~~~~^~~~~~~~~~~~~~~~~~~
foo.cc:21:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   21 |     scanf("%d",&pos[i]);
      |     ~~~~~^~~~~~~~~~~~~~

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